Sometimes luck makes you the richest person on the earth.
How do these growth services work?
No, in start you follow a lot of people and in return you want them to follow you back, these apps/tool helps to filter those who aren't following and instead of manually browsing, offer one click option.
By "those who aren't following" do you mean filter out people who don't follow anyone or do you mean unfollow people whom you followed but they did not follow you back?
Is it some app
There are other ways to grow your Twitter accounts, is that the first method you tried, or the one you prefered?
Very time consuming
Currently i am following manual follow unfollow, but so far has got like 200 following in one week with like 20 tweet a day, although all of following in my niche only.
Aren’t those accounts completely useless for conversion? I could be wrong, genuine question.
No, the core purpose is to gain initial boost, no one takes a account with 200 followers seriously and TBH i am gonna this account once it has got 50k followers
